Within the medical field, and especially in hospital environments, controlling the spread of potentially pathogenic organisms is an important concern. A number of studies have shown that the risk of infection due to the spread of disease organisms is a serious human health problem. Infections can be transferred by contact with surfaces upon which organisms can be deposited by handling by patients or hospital staff, or by airborne dispersion after a cough or sneeze. The risk of infection is further exacerbated by the confined space of typical hospitals, and by the fact that people in hospitals may have an impaired ability to resist infection due to their own health problems. In some cases as well, the infectious organisms are sometime resistant to commonly used antibiotics, so called super-bugs, and so remediation of the infection through medical intervention may be difficult, if not impossible.
As a result, it is common practice in modern day medical setting to take appropriate measures to reduce the risk of infection. Such measures include hand washing after contact with patients, frequent cleaning of floors, walls and furniture with disinfecting solutions, and the use of disposable products. The use of disposable plastic syringes, cutlery and beverage containers are but a few examples of products designed for single use in order to reduce the risk of spreading pathogens, and which through use become biomedical waste.
Biomedical waste also comprises such things as blood and blood products, tissues resected during surgery, as well as single use items used and discarded in the normal course of surgical procedures. It is well-recognized that contact with human fluids such as blood is a significant risk factor in the spread of the human immunodeficiency virus (HIV) that causes the disease acquired immune deficiency syndrome (AIDS).
It is well recognized that health hazards are posed by the handling and disposal of biomedical wastes, and that care must be exercised in handling such waste and in the disposal thereof. It is desirable and mandated in many jurisdictions that biomedical waste be processed, typically by incineration, to destroy pathogens. Incineration requires significant amounts of energy, and also releases potentially harmful combustion products into the atmosphere.
Alternatively, chemical sterilizing solutions can also be used to destroy pathogens in biomedical waste. These chemicals, being themselves toxic, pose added risks to those whose responsibility it is to handle biomedical wastes, as well as a risk to the environment upon their disposal.
Ozone is also well known as having disinfecting properties, and is well known as a sterilizing agent in certain applications. Ozone is considered very safe as evidenced by the approval of the U.S. Food & Drug Administration for use in treating food products. Ozone is a chemically active radical species of oxygen, commonly produced by ionization of either air or pure oxygen. Unlike conventional disinfecting chemicals, ozone does not form hazardous disinfectant by-products that are harmful to the environment or are toxic to animals and humans. Once ozone has fully reacted with substances in water or air, excess gas decomposes quickly to normal oxygen and is reabsorbed into the atmosphere. Commercial ozone generators are available which economically produce significant amounts of ozone.
The use of ozone in the disposal of biomedical waste is disclosed in a number of prior art patents. U.S. Pat. Nos. 5,078,965 and 5,116,574 to Pearson disclose grinding the waste and adding water to create a slurry over a fluidized bed, and then bubbling ozone up through the slurry. The systems disclosed in U.S. Pat. Nos. 6,494,391 to Mosenson and 5,820,541 to Berlanga Barrera similarly add water to the ground waste, and add a disinfectant such as ozone, to the mixture. U.S. Pat. No. 5,520,888 to Berndt uses a slush or slurry of waste and ice-containing ozone to sterilize medical waste.
Largely for reasons of economy, present waste practices in hospitals and the like include segregation of waste into general waste and biomedical waste with the biomedical waste being processed as such, and the general waste being processed as ordinary garbage and taken to landfills and disposal sites with no treatment. Typically, biomedical waste must be packaged and transported according to strict regulations in order to move same from the source, such as a hospital or the like, to off-site processing.
Such segregation is subject to human error, and as well general waste is often in contact with biomedical waste prior to segregation. Further such segregation lengthens the time between creation of the biomedical waste and treatment thereof. Pathogens therefore have an extended time in which to multiply prior to treatment, thereby increasing the number of pathogens that the treatment process must inactivate. As well, waste management personnel are exposed to these pathogens during the common manual separation of biomedical waste from general waste.